FIGURE 2.

Tethered Xenopus CCR4 and CAF1 repressed translation of an adenylated luciferase mRNA. A, mRNA encoding MS2 fusion proteins of interest were injected into oocytes. The oocytes were incubated for 6 h to allow translation of the fusion protein, followed by co-injection with two reporter mRNAs. The firefly luciferase reporter mRNA contained three MS2-binding sites in the 3′-UTR and a poly(A) tail of 39 adenosines; the Renilla luciferase reporter mRNA lacked the MS2-binding sites and was used as a control. After 16 h of incubation, the levels of firefly and Renilla luciferase were measured. B, top panel, relative repression of firefly luciferase translation by each protein. The values were normalized to firefly luciferase activity without an MS2 fusion protein expressed. The error bars were derived from analysis of four sets of four oocytes within the same experiment. Middle panel, relative translational activity of Renilla mRNA when expressed with each fusion protein. Renilla and firefly luciferase levels were normalized the same way. Bottom panel, lysates equivalent to two oocytes were loaded in each lane and analyzed by Western blotting with α-HA-11 and α-actin.